| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board and a manufacturing method of the same, which can achieve a fine pitch of a wiring layer.SOLUTION: A wiring board 10 comprises: a core layer 11; a through hole 11X in the core layer; a first metal layer 12b which extend on an internal surface of the through hole and one surface and the other surface of the core layer; a second metal layer 12c formed on each first metal layer; a third metal layer 12d formed on the second metal layer on the one surface of the core layer; and a fourth metal layer 13d formed on the second metal layer on the other surface of the core layer. In the through hole, the second metal layer is formed to cover the first metal layer on the internal surface of the through hole and occupy a central part of the through hole. On the one surface side of the core layer, a first wiring layer 12 including the first, the second and the third metal layers is formed, and on the other surface side of the core layer, a second wiring layer 13 including the first, the second and the fourth metal layers is formed. In the through hole, a through-hole interconnection 14 including the first, the second, the third and the fourth metal layers is formed. |
